Burglar-alarm.



P ATENTED FEB. 21, 1905.

H. BLANK.

BURGLAR ALARM.

APPLICATION FILED 1130. 21, 1903.

UNITED STATES Patented February 21, 1905.

PATENT OFFICE.

BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 783,399, dated February21. 1905 Application filed December 21, 1903. Serial No. 185,957.

To (all 11/71/0777! it may concern.-

Be it known that l, HENRY BLANK, a subject of the Emperor of Germany,residing at Richmond Hill, in the county of Queens and State of NewYork, have invented certain new and useful Improvements inBurglar-Alarms;

and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to burglar-alarms; and it consists generally of thenovel construction and arrangement of the several parts, as will behereinafter described and claimed.

The device is intended to be used in connection with an electrical-bellcircuit; and one of the principal objects of the invention is tosimplify and cheapen its cost of production without in any degreeimpairing its efliciency and reliability.

Other objects ofthe invention will become apparent upon a furtherdescription thereof.

In the drawings, Figure 1 is a diagrammatic view of my improved alarm,showing its application to both a window and a door; Fig. 2, alongitudinal sectional view of the device for use on a door, and Fig. 3a similar view of the device for use in a window.

Referring to the several views, the numeral 1 indicates the sill of awindow, and 2 the lower sash thereof. The window-sill is provided at anyconvenient or desired point with a suitable recess or aperture 3, inwhich is seated a shell or casing 4, having a flanged head 5, providedwith screw-holes for the reception of screws, by means of which theshell is fastened in its seat. Fitted in the open end of the shell is aninsulating-plug 6, to which is attached a pair of spring-contacts 7 7,and leading in through suitable perforations in the plug are wires 8 8,one of which is connected with spring-contact 7 and the other withspring-contact 7. The flanged head is provided with an elongatedaperture 9, through which a contact-breaking plug 10 may be insertedbetween the spring-contacts to break the contact, and thereby open thebell-circuit. The insulating-plug 10 is attached to the lower sash at asuitable point by means of-a cord or chain 11, so that when the sash israised the plug will be withdrawn and the circuit closed. The closing ofthe circuit sets the bell ringing, and it will continue to ring untilthe plug is again inserted.

The wire 8 leads to one pole of a battery 12 and the wire 8 to a bell13, while a wire It connects the bell with the other pole of thebattery.

\Vhen the device is applied to a door, l prefer to provide suitablemeans by which it may be operated from the outside by the proper person,so as to allow the door being opened without ringing thealarm. Toaccomplish this object, I increase the length of the shell or case I andinclose itin a suitable casing 15, provided with an apertured flangedhead 16,

said head being provided with holes for the reception of screws. In thisinstance the flanged head 5 is dispensed with and instead thereof theshell L is provided with two parallel bars 17 17, spaced slightly apartto allow ahinged contact-breaking plug l8 to be forced or insertedbetween the spring-contacts 7 7 to hold the circuit open. The shell L isrotatabl y secured within the casing by a pin 19, working in atransverse slot 20 in said casing. The shell 4 is provided with anaperture 2i and the casing with a transverse slot 22, through which thewires 8 8 pass to the spring-contacts, the slot 22 being of alengthsuflicient to permit the free play of the wires and to prevent theirentanglement when the shell I is rotated. The bore at the inner end ofthe shell I is squared to receive a square rod 23, which has its innerend provided with a tang 2%, passing through the closed end of a thimble25, which is secured in the outer end of a casing 26, which telescopesin the casing 15. The tang 24: is secured in a rotatable disk 27,fitting in the bottom of the thiinble, and said disk is provided on itsouter surface with four lugs 28, which, together with tumblers 29 on theinner wall of the thimble, constitute a lock, which by means of asuitable key may be manipulated to rotate the bar, and thus permit thedevice to be thrown out of operation.

In applying the device to a door a hole 30 is bored through thedoor-frame and one seetion or member of the device is inserted, afterwhich the othersection or member is inserted. The two sections are thensecured to the respective edges of the door-frame, the casing 26 beingprovided with a flanged head 31, having holes for securing-screws. insetting the device the hinged contactbreaker extends across the edge ofthe door, so that the wrongful opening of the door will force the hingedcontact-breaker from between the spring-contacts and closing the circuitcause an alarm to be sounded, the alarm continuing until thecontact-breaker is again placed between the spring-contacts.

'lhe operation of the device is obvious and needs no further descriptionor explanation other than to state that the shell 4 may be retated fromthe inside to throw the device out of operative position by simplycatching hold of the bars and. turning the shell L until the hingedcontact-breaker is removed from its position across the edges of thedoor.

Various modifications or changes in the details of construction may bemade without departing from the spirit of my invention or sacrificingthe principle thereof.

Having thus fully described my invention, what 1 claim, and desire tosecure by Letters Patent, is

l. in an electric burglar-alarm, the combination with an opening havinga closing member, of a shell or casing secured in the frame of theopening, an insulating-plug fixed in one end of the shell, a pair ofspring-contacts secured to said plug, and a contact-plug adapted tobreak the circuit, said contact-plug being so located and arranged thatthe opening of the closing member will sound an alarm.

2. in a burglar-alarm device, the combination vwith an electric-bellcircuit, of two telescopic members, a shell or casing rotatably securedwithin one member, spring-contacts secured within the shell or casing, acontactbreaker arranged to be operated by the opening of a door to soundan alarm, and means for throwing the device out of operative position.

3. in a burglar-alarm device, the combination with an electric-bellcircuit, of two telescopic members, a shell or casing rotatably securedwithin one member, spring-contacts secured within the shell or casing, acontactbrealrer arranged to be operated to open the circuit, and arotatable bar adapted to operate to throw the device out of operativeposition. In testlmony whereof l allix my signature in the presence oftwo witnesses.

HENRY BLANK.

\Vitnesses:

HENRY Hanson), (1} some t: DOAN 'licl-umnn.

